vitalybuka updated this revision to Diff 479992.
vitalybuka added a comment.
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Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D139296/new/
https://reviews.llvm.org/D139296
Files:
clang/lib/CodeGen/CGCall.cpp
clang/test/CodeGen/cleanup-destslot-simple.c
clang/test/CodeGen/msan-param-retval.c
Index: clang/test/CodeGen/msan-param-retval.c
===================================================================
--- clang/test/CodeGen/msan-param-retval.c
+++ clang/test/CodeGen/msan-param-retval.c
@@ -23,13 +23,20 @@
return 1;
}
-// CHECK: define dso_local i32 @foo() #0 {
-// CHECK: @__msan_retval_tls
+// CLEAN: define dso_local i32 @foo() #0 {
+// NOUNDEF: define dso_local noundef i32 @foo() #0 {
+// CLEAN: @__msan_retval_tls
+// NOUNDEF_ONLY: @__msan_retval_tls
+// EAGER-NOT: @__msan_retval_tls
// CHECK: }
int noret() {
}
-// CHECK: define dso_local i32 @noret() #0 {
+// CLEAN: define dso_local i32 @noret() #0 {
+// NOUNDEF: define dso_local noundef i32 @noret() #0 {
// CHECK: %retval = alloca
-// CHECK: }
\ No newline at end of file
+// CLEAN: @__msan_retval_tls
+// NOUNDEF_ONLY: @__msan_retval_tls
+// EAGER-NOT: @__msan_retval_tls
+// CHECK: }
Index: clang/test/CodeGen/cleanup-destslot-simple.c
===================================================================
--- clang/test/CodeGen/cleanup-destslot-simple.c
+++ clang/test/CodeGen/cleanup-destslot-simple.c
@@ -64,7 +64,12 @@
// CHECK-MSAN-NEXT: [[_MSLD1:%.*]] = load i32, ptr [[TMP11]], align 4, !dbg
[[DBG20]]
// CHECK-MSAN-NEXT: call void @llvm.lifetime.end.p0(i64 8, ptr nonnull
[[P]]), !dbg [[DBG22:![0-9]+]]
// CHECK-MSAN-NEXT: call void @llvm.lifetime.end.p0(i64 4, ptr nonnull
[[X]]) #[[ATTR2]], !dbg [[DBG22]]
-// CHECK-MSAN-NEXT: store i32 [[_MSLD1]], ptr @__msan_retval_tls, align 8,
!dbg [[DBG23:![0-9]+]]
+// CHECK-MSAN-NEXT: [[_MSCMP2_NOT:%.*]] = icmp eq i32 [[_MSLD1]], 0, !dbg
[[DBG23:![0-9]+]]
+// CHECK-MSAN-NEXT: br i1 [[_MSCMP2_NOT]], label [[TMP13:%.*]], label
[[TMP12:%.*]], !dbg [[DBG23]], !prof [[PROF21]]
+// CHECK-MSAN: 12:
+// CHECK-MSAN-NEXT: call void @__msan_warning_noreturn() #[[ATTR3]], !dbg
[[DBG23]]
+// CHECK-MSAN-NEXT: unreachable, !dbg [[DBG23]]
+// CHECK-MSAN: 13:
// CHECK-MSAN-NEXT: ret i32 [[TMP8]], !dbg [[DBG23]]
//
// CHECK-KMSAN-LABEL: @test(
Index: clang/lib/CodeGen/CGCall.cpp
===================================================================
--- clang/lib/CodeGen/CGCall.cpp
+++ clang/lib/CodeGen/CGCall.cpp
@@ -1798,6 +1798,13 @@
static bool HasStrictReturn(const CodeGenModule &Module, QualType RetTy,
const Decl *TargetDecl) {
+ // As-is msan can not tolerate noundef mismatch between caller and
+ // implementation. Mismatch is possible for e.g. indirect calls from C-caller
+ // into C++. Such mismatches lead to confusing false reports. To avoid
+ // expensive workaround on msan we enforce initialization event in uncommon
+ // cases where it's allowed.
+ if (Module.getLangOpts().Sanitize.has(SanitizerKind::Memory))
+ return true;
// C++ explicitly makes returning undefined values UB. C's rule only applies
// to used values, so we never mark them noundef for now.
if (!Module.getLangOpts().CPlusPlus)
Index: clang/test/CodeGen/msan-param-retval.c
===================================================================
--- clang/test/CodeGen/msan-param-retval.c
+++ clang/test/CodeGen/msan-param-retval.c
@@ -23,13 +23,20 @@
return 1;
}
-// CHECK: define dso_local i32 @foo() #0 {
-// CHECK: @__msan_retval_tls
+// CLEAN: define dso_local i32 @foo() #0 {
+// NOUNDEF: define dso_local noundef i32 @foo() #0 {
+// CLEAN: @__msan_retval_tls
+// NOUNDEF_ONLY: @__msan_retval_tls
+// EAGER-NOT: @__msan_retval_tls
// CHECK: }
int noret() {
}
-// CHECK: define dso_local i32 @noret() #0 {
+// CLEAN: define dso_local i32 @noret() #0 {
+// NOUNDEF: define dso_local noundef i32 @noret() #0 {
// CHECK: %retval = alloca
-// CHECK: }
\ No newline at end of file
+// CLEAN: @__msan_retval_tls
+// NOUNDEF_ONLY: @__msan_retval_tls
+// EAGER-NOT: @__msan_retval_tls
+// CHECK: }
Index: clang/test/CodeGen/cleanup-destslot-simple.c
===================================================================
--- clang/test/CodeGen/cleanup-destslot-simple.c
+++ clang/test/CodeGen/cleanup-destslot-simple.c
@@ -64,7 +64,12 @@
// CHECK-MSAN-NEXT: [[_MSLD1:%.*]] = load i32, ptr [[TMP11]], align 4, !dbg [[DBG20]]
// CHECK-MSAN-NEXT: call void @llvm.lifetime.end.p0(i64 8, ptr nonnull [[P]]), !dbg [[DBG22:![0-9]+]]
// CHECK-MSAN-NEXT: call void @llvm.lifetime.end.p0(i64 4, ptr nonnull [[X]]) #[[ATTR2]], !dbg [[DBG22]]
-// CHECK-MSAN-NEXT: store i32 [[_MSLD1]], ptr @__msan_retval_tls, align 8, !dbg [[DBG23:![0-9]+]]
+// CHECK-MSAN-NEXT: [[_MSCMP2_NOT:%.*]] = icmp eq i32 [[_MSLD1]], 0, !dbg [[DBG23:![0-9]+]]
+// CHECK-MSAN-NEXT: br i1 [[_MSCMP2_NOT]], label [[TMP13:%.*]], label [[TMP12:%.*]], !dbg [[DBG23]], !prof [[PROF21]]
+// CHECK-MSAN: 12:
+// CHECK-MSAN-NEXT: call void @__msan_warning_noreturn() #[[ATTR3]], !dbg [[DBG23]]
+// CHECK-MSAN-NEXT: unreachable, !dbg [[DBG23]]
+// CHECK-MSAN: 13:
// CHECK-MSAN-NEXT: ret i32 [[TMP8]], !dbg [[DBG23]]
//
// CHECK-KMSAN-LABEL: @test(
Index: clang/lib/CodeGen/CGCall.cpp
===================================================================
--- clang/lib/CodeGen/CGCall.cpp
+++ clang/lib/CodeGen/CGCall.cpp
@@ -1798,6 +1798,13 @@
static bool HasStrictReturn(const CodeGenModule &Module, QualType RetTy,
const Decl *TargetDecl) {
+ // As-is msan can not tolerate noundef mismatch between caller and
+ // implementation. Mismatch is possible for e.g. indirect calls from C-caller
+ // into C++. Such mismatches lead to confusing false reports. To avoid
+ // expensive workaround on msan we enforce initialization event in uncommon
+ // cases where it's allowed.
+ if (Module.getLangOpts().Sanitize.has(SanitizerKind::Memory))
+ return true;
// C++ explicitly makes returning undefined values UB. C's rule only applies
// to used values, so we never mark them noundef for now.
if (!Module.getLangOpts().CPlusPlus)
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